Just to confuse the issue further , here's a link to German S gauge (22.5 mm) info:
http://www.traincollectors.org...20News%20Article.htm
I have some of the East German VEB Stadtilm S gauge track and switches, which American Flyer will run on, just. It's a bit wide and the Flyer stuff tends to run between the rails but doesn't de-rail. It's stamped tinplate pressed into slotted die-cut cardboard tie strip. Or, as I call it, capitalist trains running on communist track .